Java Stat.getVersion方法代碼示例

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
/**
 * CAS更新指定節點數據內容
 * @param path  節點path
 * @param payload  數據內容
 * @param version 版本號
 * @return
 * @throws Exception
 */
@Override
public int setDataWithVersion(String path, byte[] payload, int version) throws Exception {
    try {
        Stat stat = null;
        if (version != -1) {
            stat = client.setData().withVersion(version).forPath(path, payload);
        } else {
            stat = client.setData().forPath(path, payload);
        }
        if (stat != null) {
            //logger.info("CAS設置數據成功，path：" + path );
            return stat.getVersion();
        } else {
            logger.error("CAS設置數據失敗，path：" + path);
            return -1;
        }
    } catch (KeeperException.BadVersionException ex) {
        logger.error("CAS設置數據失敗，path：" + path);
        return -1;
    }

}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
@Override
protected void modelModifiedExternally() {

    ZnodeModel znodeModel = getModel();

    if (znodeModel.isDestroyed()) {
        return;
    }

    ZnodeModelFormEditor editor = (ZnodeModelFormEditor) getEditor();
    Znode znode = znodeModel.getData();
    Stat stat = znode.getStat();

    if (!isDirty() || stat.getVersion() == editor.getLastModificationVersion()) {
        _ActiveEditor.syncZnodeModelData();
        updateToolbarLabelText();
    }
    else {
        editor.setActivePage(ID);
        setInfoText(EXTERNAL_MODIFICATION_INFO_TEXT);
    }

}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
public void processResult(int rc, String path,
        Object ctx, byte[] data, Stat stat) {
    if (rc == KeeperException.Code.NONODE.intValue()) {
        // we can just ignore because the child watcher takes care of this
        return;
    }
    if (rc != KeeperException.Code.OK.intValue()) {
        zk.getData(myNode, (Watcher)ctx, this, ctx);
    }
    int currVer = stat.getVersion();
    if (currVer != lastVer) {
        String parts[] = new String(data).split(" ", 2);
        myInstance.configure(parts[1]);
        lastVer = currVer;
    }
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
/**
 * Creates the specified node with the specified data and watches it.
 *
 * <p>Throws an exception if the node already exists.
 *
 * <p>The node created is persistent and open access.
 *
 * <p>Returns the version number of the created node if successful.
 *
 * @param zkw zk reference
 * @param znode path of node to create
 * @param data data of node to create
 * @return version of node created
 * @throws KeeperException if unexpected zookeeper exception
 * @throws KeeperException.NodeExistsException if node already exists
 */
public static int createAndWatch(ZooKeeperWatcher zkw,
    String znode, byte [] data)
throws KeeperException, KeeperException.NodeExistsException {
  try {
    zkw.getRecoverableZooKeeper().create(znode, data, createACL(zkw, znode),
        CreateMode.PERSISTENT);
    Stat stat = zkw.getRecoverableZooKeeper().exists(znode, zkw);
    if (stat == null){
      // Likely a race condition. Someone deleted the znode.
      throw KeeperException.create(KeeperException.Code.SYSTEMERROR,
          "ZK.exists returned null (i.e.: znode does not exist) for znode=" + znode);
    }
   return stat.getVersion();
  } catch (InterruptedException e) {
    zkw.interruptedException(e);
    return -1;
  }
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
@Test
public void testSetData() throws Exception {
    final ZooKeeper zk = createClient();
    ZooKeeperMain zkMain = new ZooKeeperMain(zk);
    String cmdstring1 = "create -e /node4 data";
    String cmdstring2 = "set /node4 " + "data";
    String cmdstring3 = "delete /node4";
    Stat stat = new Stat();
    int version = 0;
    zkMain.cl.parseCommand(cmdstring1);
    Assert.assertTrue(zkMain.processZKCmd(zkMain.cl));
    stat = zk.exists("/node4", true);
    version = stat.getVersion();
    zkMain.cl.parseCommand(cmdstring2);
    Assert.assertFalse(zkMain.processZKCmd(zkMain.cl));
    stat = zk.exists("/node4", true);
    Assert.assertEquals(version + 1, stat.getVersion());
    zkMain.cl.parseCommand(cmdstring3);
    Assert.assertFalse(zkMain.processZKCmd(zkMain.cl));
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
/**
 * Update state as to indicate that a lock is held
 * @param createdZNode The lock znode
 * @throws IOException If an unrecoverable ZooKeeper error occurs
 */
protected void updateAcquiredLock(String createdZNode) throws IOException {
  Stat stat = new Stat();
  byte[] data = null;
  Exception ex = null;
  try {
    data = ZKUtil.getDataNoWatch(zkWatcher, createdZNode, stat);
  } catch (KeeperException e) {
    LOG.warn("Cannot getData for znode:" + createdZNode, e);
    ex = e;
  }
  if (data == null) {
    LOG.error("Can't acquire a lock on a non-existent node " + createdZNode);
    throw new IllegalStateException("ZNode " + createdZNode +
        "no longer exists!", ex);
  }
  AcquiredLock newLock = new AcquiredLock(createdZNode, stat.getVersion());
  if (!acquiredLock.compareAndSet(null, newLock)) {
    LOG.error("The lock " + fullyQualifiedZNode +
        " has already been acquired by another process!");
    throw new IllegalStateException(fullyQualifiedZNode +
        " is held by another process");
  }
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
/**
 * 獲得節點的version號，如果節點不存在，返回 -1
 * @param path
 * @return
 * @throws Exception
 */
@Override
public int getVersion(String path) throws Exception {
    Stat stat = this.getStat(path);
    if (stat != null) {
        return stat.getVersion();
    } else {
        return -1;
    }
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
@PUT
@Produces( { MediaType.APPLICATION_JSON, "application/javascript",
        MediaType.APPLICATION_XML })
@Consumes(MediaType.APPLICATION_OCTET_STREAM)
public Response setZNode(
        @PathParam("path") String path,
        @QueryParam("callback") String callback,
        @DefaultValue("-1") @QueryParam("version") String versionParam,
        @DefaultValue("base64") @QueryParam("dataformat") String dataformat,
        @DefaultValue("false") @QueryParam("null") String setNull,
        @Context UriInfo ui, byte[] data) throws InterruptedException,
        KeeperException {
    ensurePathNotNull(path);

    int version;
    try {
        version = Integer.parseInt(versionParam);
    } catch (NumberFormatException e) {
        throw new WebApplicationException(Response.status(
                Response.Status.BAD_REQUEST).entity(
                new ZError(ui.getRequestUri().toString(), path
                        + " bad version " + versionParam)).build());
    }

    if (setNull.equals("true")) {
        data = null;
    }

    Stat stat = zk.setData(path, data, version);

    ZStat zstat = new ZStat(path, ui.getAbsolutePath().toString(), null,
            null, stat.getCzxid(), stat.getMzxid(), stat.getCtime(), stat
                    .getMtime(), stat.getVersion(), stat.getCversion(),
            stat.getAversion(), stat.getEphemeralOwner(), stat
                    .getDataLength(), stat.getNumChildren(), stat
                    .getPzxid());

    return Response.status(Response.Status.OK).entity(
            new JSONWithPadding(zstat, callback)).build();
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
/**
 *
 * @param zkw zk reference
 * @param region region to be closed
 * @param expectedVersion expected version of the znode
 * @return true if the znode exists, has the right version and the right state. False otherwise.
 * @throws KeeperException
 */
public static boolean checkClosingState(ZooKeeperWatcher zkw, HRegionInfo region,
                                        int expectedVersion) throws KeeperException {

  final String encoded = getNodeName(zkw, region.getEncodedName());
  zkw.sync(encoded);

  // Read existing data of the node
  Stat stat = new Stat();
  byte[] existingBytes = ZKUtil.getDataNoWatch(zkw, encoded, stat);

  if (existingBytes == null) {
    LOG.warn(zkw.prefix("Attempt to check the " +
        "closing node for " + encoded +
        ". The node does not exist"));
    return false;
  }

  if (expectedVersion != -1 && stat.getVersion() != expectedVersion) {
    LOG.warn(zkw.prefix("Attempt to check the " +
        "closing node for " + encoded +
        ". The node existed but was version " + stat.getVersion() +
        " not the expected version " + expectedVersion));
    return false;
  }

  RegionTransition rt = getRegionTransition(existingBytes);

  if (!EventType.M_ZK_REGION_CLOSING.equals(rt.getEventType())) {
    LOG.warn(zkw.prefix("Attempt to check the " +
        "closing node for " + encoded +
        ". The node existed but was in an unexpected state: " + rt.getEventType()));
    return false;
  }

  return true;
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
/**
 * Pulls data from ZooKeeper.  If isInit is false, it will only parse the
 * next secret and version.  If isInit is true, it will also parse the current
 * and previous secrets, and the next rollover date; it will also init the
 * secrets.  Hence, isInit should only be true on startup.
 * @param isInit  see description above
 */
private synchronized void pullFromZK(boolean isInit) {
  try {
    Stat stat = new Stat();
    byte[] bytes = client.getData().storingStatIn(stat).forPath(path);
    ByteBuffer bb = ByteBuffer.wrap(bytes);
    int dataVersion = bb.getInt();
    if (dataVersion > DATA_VERSION) {
      throw new IllegalStateException("Cannot load data from ZooKeeper; it"
              + "was written with a newer version");
    }
    int nextSecretLength = bb.getInt();
    byte[] nextSecret = new byte[nextSecretLength];
    bb.get(nextSecret);
    this.nextSecret = nextSecret;
    zkVersion = stat.getVersion();
    if (isInit) {
      int currentSecretLength = bb.getInt();
      byte[] currentSecret = new byte[currentSecretLength];
      bb.get(currentSecret);
      int previousSecretLength = bb.getInt();
      byte[] previousSecret = null;
      if (previousSecretLength > 0) {
        previousSecret = new byte[previousSecretLength];
        bb.get(previousSecret);
      }
      super.initSecrets(currentSecret, previousSecret);
      nextRolloverDate = bb.getLong();
    }
  } catch (Exception ex) {
    LOG.error("An unexpected exception occurred while pulling data from"
            + "ZooKeeper", ex);
  }
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
public long updateReloadTaskItemFlag(String taskType) throws Exception{
  	String baseTaskType = ScheduleUtil.splitBaseTaskTypeFromTaskType(taskType);
String zkPath = this.PATH_BaseTaskType + "/" + baseTaskType 
        + "/" + taskType + "/" + this.PATH_Server;
Stat stat = this.getZooKeeper().setData(zkPath,"reload=true".getBytes(),-1);
return stat.getVersion();

  }
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
public long getReloadTaskItemFlag(String taskType) throws Exception{
  	String baseTaskType = ScheduleUtil.splitBaseTaskTypeFromTaskType(taskType);
String zkPath = this.PATH_BaseTaskType + "/" + baseTaskType 
        + "/" + taskType + "/" + this.PATH_Server;
Stat stat = new Stat();
this.getZooKeeper().getData(zkPath, false, stat);
  	return stat.getVersion();
  }
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
/**
 * Try to own the task by transitioning the zk node data from UNASSIGNED to OWNED.
 * <p>
 * This method is also used to periodically heartbeat the task progress by transitioning the node
 * from OWNED to OWNED.
 * <p>
 * @param isFirstTime shows whther it's the first attempt.
 * @param zkw zk wathcer
 * @param server name
 * @param task to own
 * @param taskZKVersion version of the task in zk
 * @return non-negative integer value when task can be owned by current region server otherwise -1
 */
protected static int attemptToOwnTask(boolean isFirstTime, ZooKeeperWatcher zkw,
    ServerName server, String task, RecoveryMode mode, int taskZKVersion) {
  int latestZKVersion = FAILED_TO_OWN_TASK;
  try {
    SplitLogTask slt = new SplitLogTask.Owned(server, mode);
    Stat stat = zkw.getRecoverableZooKeeper().setData(task, slt.toByteArray(), taskZKVersion);
    if (stat == null) {
      LOG.warn("zk.setData() returned null for path " + task);
      SplitLogCounters.tot_wkr_task_heartbeat_failed.incrementAndGet();
      return FAILED_TO_OWN_TASK;
    }
    latestZKVersion = stat.getVersion();
    SplitLogCounters.tot_wkr_task_heartbeat.incrementAndGet();
    return latestZKVersion;
  } catch (KeeperException e) {
    if (!isFirstTime) {
      if (e.code().equals(KeeperException.Code.NONODE)) {
        LOG.warn("NONODE failed to assert ownership for " + task, e);
      } else if (e.code().equals(KeeperException.Code.BADVERSION)) {
        LOG.warn("BADVERSION failed to assert ownership for " + task, e);
      } else {
        LOG.warn("failed to assert ownership for " + task, e);
      }
    }
  } catch (InterruptedException e1) {
    LOG.warn("Interrupted while trying to assert ownership of " + task + " "
        + StringUtils.stringifyException(e1));
    Thread.currentThread().interrupt();
  }
  SplitLogCounters.tot_wkr_task_heartbeat_failed.incrementAndGet();
  return FAILED_TO_OWN_TASK;
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
/**
 * Deletes an existing unassigned node that is in the specified state for the
 * specified region.
 *
 * <p>If a node does not already exist for this region, a
 * {@link org.apache.zookeeper.KeeperException.NoNodeException} will be thrown.
 *
 * <p>No watcher is set whether this succeeds or not.
 *
 * <p>Returns false if the node was not in the proper state but did exist.
 *
 * <p>This method is used when a region finishes opening/closing.
 * The Master acknowledges completion
 * of the specified regions transition to being closed/opened.
 *
 * @param zkw zk reference
 * @param encodedRegionName region to be deleted from zk
 * @param expectedState state region must be in for delete to complete
 * @param serverName the expected region transition target server name
 * @param expectedVersion of the znode that is to be deleted.
 *        If expectedVersion need not be compared while deleting the znode
 *        pass -1
 * @throws KeeperException if unexpected zookeeper exception
 * @throws KeeperException.NoNodeException if node does not exist
 */
public static boolean deleteNode(ZooKeeperWatcher zkw, String encodedRegionName,
    EventType expectedState, ServerName serverName, int expectedVersion)
throws KeeperException, KeeperException.NoNodeException {
  if (LOG.isTraceEnabled()) {
    LOG.trace(zkw.prefix("Deleting existing unassigned " +
      "node " + encodedRegionName + " in expected state " + expectedState));
  }
  String node = getNodeName(zkw, encodedRegionName);
  zkw.sync(node);
  Stat stat = new Stat();
  byte [] bytes = ZKUtil.getDataNoWatch(zkw, node, stat);
  if (bytes == null) {
    // If it came back null, node does not exist.
    throw KeeperException.create(Code.NONODE);
  }
  RegionTransition rt = getRegionTransition(bytes);
  EventType et = rt.getEventType();
  if (!et.equals(expectedState)) {
    LOG.warn(zkw.prefix("Attempting to delete unassigned node " + encodedRegionName + " in " +
      expectedState + " state but node is in " + et + " state"));
    return false;
  }
  // Verify the server transition happens on is not changed
  if (serverName != null && !rt.getServerName().equals(serverName)) {
    LOG.warn(zkw.prefix("Attempting to delete unassigned node " + encodedRegionName
      + " with target " + serverName + " but node has " + rt.getServerName()));
    return false;
  }
  if (expectedVersion != -1
      && stat.getVersion() != expectedVersion) {
    LOG.warn("The node " + encodedRegionName + " we are trying to delete is not" +
      " the expected one. Got a version mismatch");
    return false;
  }
  if(!ZKUtil.deleteNode(zkw, node, stat.getVersion())) {
    LOG.warn(zkw.prefix("Attempting to delete " +
        "unassigned node " + encodedRegionName + " in " + expectedState +
        " state but after verifying state, we got a version mismatch"));
    return false;
  }
  LOG.debug(zkw.prefix("Deleted unassigned node " +
      encodedRegionName + " in expected state " + expectedState));
  return true;
}
 

import org.apache.zookeeper.data.Stat; //導入方法依賴的package包/類
/**
 * Confirm an existing unassigned node for the specified region which is
 * currently in the OPENING state to be still in the OPENING state on
 * the specified server.
 *
 * <p>If for some reason the check fails, the method returns -1. Otherwise,
 * the version of the node (same as the expected version) is returned.
 *
 * <p>This method can fail and return -1 for three different reasons:
 * <ul><li>Unassigned node for this region does not exist</li>
 * <li>Unassigned node for this region is not in OPENING state</li>
 * <li>After verifying OPENING state, the server name or the version of the
 * doesn't match)</li>
 * </ul>
 *
 * <p>Does not set any watches.
 *
 * <p>This method should only be used by a RegionServer when initiating an
 * open of a region after receiving an OPEN RPC from the Master.
 *
 * @param zkw zk reference
 * @param region region to be transitioned to opening
 * @param serverName server transition happens on
 * @return version of node after transition, -1 if unsuccessful transition
 * @throws KeeperException if unexpected zookeeper exception
 */
public static int confirmNodeOpening(ZooKeeperWatcher zkw,
    HRegionInfo region, ServerName serverName, int expectedVersion)
throws KeeperException {

  String encoded = region.getEncodedName();
  if(LOG.isDebugEnabled()) {
    LOG.debug(zkw.prefix("Attempting to retransition opening state of node " +
        HRegionInfo.prettyPrint(encoded)));
  }

  String node = getNodeName(zkw, encoded);
  zkw.sync(node);

  // Read existing data of the node
  Stat stat = new Stat();
  byte [] existingBytes = ZKUtil.getDataNoWatch(zkw, node, stat);
  if (existingBytes == null) {
    // Node no longer exists.  Return -1. It means unsuccessful transition.
    return -1;
  }
  RegionTransition rt = getRegionTransition(existingBytes);

  // Verify it is the expected version
  if (expectedVersion != -1 && stat.getVersion() != expectedVersion) {
    LOG.warn(zkw.prefix("Attempt to retransition the opening state of the " +
        "unassigned node for " + encoded + " failed, " +
        "the node existed but was version " + stat.getVersion() +
        " not the expected version " + expectedVersion));
    return -1;
  }

  // Verify it is in expected state
  EventType et = rt.getEventType();
  if (!et.equals(EventType.RS_ZK_REGION_OPENING)) {
    String existingServer = (rt.getServerName() == null)
        ? "<unknown>" : rt.getServerName().toString();
    LOG.warn(zkw.prefix("Attempt to retransition the opening state of the unassigned node for "
        + encoded + " failed, the node existed but was in the state " + et +
        " set by the server " + existingServer));
    return -1;
  }

  return expectedVersion;
}